viernes, 10 de marzo de 2017

Astronomers discover 7 Earth-sized planets

Astronomers have discovered seven Earth-sized planets orbiting a single star - a record number.

Self-study activity:
Watch the video and say whether the statements below are true or false.

1. These planets orbit around a star much stronger than the Sun.2. The new planets can perfectly be seen from the Earth.3. Water has been spotted on these planets.4. In the last 25 years, more than 3,000 planets have been discovered.5. The planets are 40 million kilometres away.6. To reach these planets would take around 70,000 years.7. Huge new telescopes have started operating recently, which makes it possible to have a closer look at the new planets.

An artist's impression of a startling discovery deep in space: Around a faint and distant star much weaker than our Sun, it’s a collection of planets that are surprisingly similar to Earth. In all, seven of these worlds have been spotted. And astronomers think it may change the way we look at the night sky. An array of telescopes kept watch on one point in space, and what the scientists were looking for were tiny clues about the light of a particular start becoming dimmer on a regular basis as planets orbitted in front of it. They can't see these new worlds but they know they're there.We were extremely excited. This is the biggest amount of planets that we’ve found in one go that look like the Earth in composition, size and mass. All seven are close enough to the star and far enough to the star that they could host liquid water and that, that's just incredible.This is the latest revelation in a wave of discoveries over the past 25 years of new worlds that exist in solar systems beyond our own. The total of these distant planets now stands at well over 3,000. What makes this discovery so unusual is the sheer number of new worlds spotted in one go, seven in all, and crucially at just the right temperature for liquid water to exist at the surface. Three of them are in what's called the habitable zone, which raises the tantalizing possibility that they could conceivably host life. But we won't be getting there in a hurry. They're 40 light-years away. To reach them, using the rockets we have now, would take something like 700,000 years.There's so much to find out about these worlds, whether the artist’s impressions are right, whether it's possible that the conditions for life do exist, and astronomers say there'll be a huge effort to try to find out. The more we look, the more planets we find, and the more Earth-like planets we find. But this is especially exciting because this sort of of ultra-cool star that we've discovered, they're quite populous throughout our galaxy and it's the first time we’ve found planets going around a star like this, and we've found seven of them.The best hope lies with huge new telescopes that will come into service soon, improving the chances of getting a really close look at these alien worlds to see, for example, if they do have oceans and maybe, just maybe, discover if there are some hints about life. David Shukman, BBC News.